The present invention relates to an ion generator adapted to generate ozone by ionizing air introduced into a casing.
There have been used ion generators designed to supply ionized air to intake manifolds of internal combustion engines for the purposes of enhancing the combustion efficiency thereof, improving the fuel economy and reducing the air pollution.
FIG. 10 is a sectional view showing an exemplary prior-art ion generator. A casing 80 of this ion generator includes a cylinder body 89 which is formed from stainless steel or the like and the opposite ends of which are closed by caps 84, 85. One 84 of the caps is formed with an intake port 86 whereas the other cap 85 is formed with an exhaust port 87. The ion generator has an arrangement wherein a gap between the intake port 86 and the exhaust port 87 defines an air-flow passage A in which a high-voltage generator 88 is disposed on an upstream side and an ionization electrode I is disposed on a downstream side.
The ionization electrode I includes an outside electrode 81 formed by a part of the cylinder body 89, an inside electrode 82 disposed centrally of the outside electrode 81, and a pair of disk-like support members 83 for supporting the inside electrode 82. The inside electrode 82 includes a conductive shaft 82a bridging the pair of support members 83, and a plurality of star electrodes 82b axially mounted on the conductive shaft 82a at regular space intervals. The inside electrode 82 is connected to one pole of the high-voltage generator 88 while the outside electrode 81 is connected to the other pole of the high-voltage electrode 88.
The pair of support members 83 are formed from an insulating material. The support members are each formed with vent holes 83c extended through a side thereof and arranged at given space intervals along a circumference about the shaft 82a such that the air introduced into the casing 80 through the intake port 86 is guided to the exhaust port 87 by the vent holes.
In the ion generator, a high voltage is applied between the outside electrode 81 and the inside electrode 82 of the ionization electrode I for effecting corona discharge therebetween such that the air in the electrode is ionized to produce ozone.
Unfortunately, the ionization electrode I of FIG. 10 suffers a poor air-ionization efficiency because a majority of the corona discharge develops from the star electrodes 82b at the opposite ends of the shaft 82a while the other star electrodes 82b between these electrodes do not function effectively. The ionization electrode also suffers the following problem. If the star electrodes are eccentric with respect to the outside electrode 81 due to the working errors or mounting errors of the outside electrode 81 and the inside electrode 82, the corona discharge will concentrate on some of the pointed ends of the star electrodes 82b that are the closest to the outside electrode 81, thus developing into spark discharge, which will cause burn of an electric circuit component and the like of the high-voltage generator 88. Furthermore, even if the discharge does not concentrate on one place, there occurs an instable corona discharge rather closer to the spark discharge. Hence, a measure must be taken to provide the stable discharge by increasing the current value of a primary winding of a transformer incorporated in the high-voltage generator 88. This results in an increased power consumption.
FIG. 11 is a sectional view showing an ionization electrode D of another prior-art ion generator.
A casing 90 of the ionization electrode D includes a cylinder body 91 formed from a resin material and a pair of closure plates 92 for closing opposite ends of the cylinder body 91, the closure plate formed with a plurality of vent holes 92a. 
The ionization electrode D includes a hollow brass electrode 93 attached to one of the closure plates 92 of the casing 90, and a spherical electrode portion 94 attached to the other closure plate 92. The spherical electrode portion 94 consists of a spherical electrode 94a and a support member 94b. A plurality of rectangular fins 93a formed from a thin stainless-steel sheet are attached to an outer periphery of a distal end of the hollow electrode 93, the fins arranged with equal spacing.
The ionization electrode D operates as follows. A DC positive high voltage is applied between the hollow electrode 93 and the spherical electrode portion 94 while allowing for an air flow from the hollow electrode 93 to the spherical electrode portion 94, thereby effecting corona discharge B from end faces of the fins 93a toward the spherical electrode 94a, the end faces opposing the spherical electrode portion 94. The air within the electrode D is ionized by the corona discharge B to produce ozone.
The ionization electrode D of FIG. 11 involves a cumbersome working of the fins 93a, which are insufficient in the ability to generate discharge unless they are so thin as about 0.1 mm. In addition, this electrode also suffers the same drawbacks as the ionization electrode I of FIG. 10. That is, the discharge concentrates on one place due to the working errors or mounting errors of the electrodes, resulting in the burn of the electric circuit component and the like. Even if the discharge does not concentrate on one place, the current value of the primary winding of the transformer must be increased and hence, an increased power consumption results.
Accordingly, it is an object of the invention to provide an ion generator adapted for stable generation of corona discharge despite the working errors or mounting errors of the electrodes.
It is another object of the invention to provide an ion generator allowing for the reduction of the current value of the primary winding of the transformer thereby achieving the reduction of power consumption.
It is still another object of the invention to provide an ion generator adapted to improve the air ionization efficiency.
An ion generator according to the invention for achieving the above objects comprises a casing having an intake port and an exhaust port; an ionization electrode contained in the casing and including a first plate-like pole having a plurality of pointed ends at least on a part of its edge and a second pole opposing a flat surface of the first pole; and a high-voltage generator for applying a high voltage to the ionization electrode (claim 1).
According to the ion generator of this arrangement, the discharge is prevented from concentrating on some of the pointed ends of the first pole that are closer to the second pole than the rest due to the working errors or mounting errors of the poles. This is presumed to be the result of the arrangement wherein the second pole in the ionization electrode opposes the flat surface of the first pole or the first pole does not present its pointed ends directly to the second pole. That is, the corona discharge has a lower directivity than in the arrangement wherein the pointed ends of the first pole are in direct face-to-face relation with the second pole. Accordingly, the corona discharge occurs in a stable manner free from the fear of developing into the spark discharge. Thus, the ion generator of the invention eliminates the possibility of troubles such as the burn of the electric circuit component of the high-voltage generator. Furthermore, the inventive ion generator is adapted to save power by reducing the current value of the primary winding of the transformer and to improve the air ionization efficiency.
According to one preferred mode of the invention, the ion generator has an arrangement wherein the second pole has a discharge surface three-dimensionally curved into a convex surface (claim 2). The ion generator features a further lowered directivity of the corona discharge. This leads to an even greater effect to prevent the discharge from concentrating on some of the pointed ends due to the working errors or mounting errors of the poles, ensuring a more stable corona discharge. As a result, the current value of the primary winding of the transformer can be further decreased while the air ionization efficiency is further increased.
It is preferred in the ion generator that the first pole comprises a star electrode whereas the second pole has a spheric discharge surface (claim 3). This arrangement also ensures a more stable generation of corona discharge.
The ion generator may have an arrangement wherein the second pole comprises a flat plate inclined at a predetermined angle relative to the flat surface of the first pole (claim 4). The arrangement provides an even greater effect to prevent the discharge from concentrating on some of the pointed ends due to the working errors or mounting errors of the poles. This eliminates the fear that the corona discharge may develop into the spark discharge, ensuring the stable generation of corona discharge.
Another ion generator according to the invention comprises a casing having an intake port and an exhaust port; an ionization electrode contained in the casing and including a first plate-like pole having a plurality of sawtooth-like pointed ends arranged linearly, and a second pole having a discharge surface defined by a cylinder or a part thereof and its generatrix extended in parallel with the pointed ends of the first pole; and a high-voltage generator for applying a high voltage to the ionization electrode (claim 5). In this ion generator as well, the first pole does not present its pointed ends directly to the second pole whereas the discharge surface of the second pole is in the form of a convex surface defined by a cylinder or a part thereof. Hence, the directivity of the corona discharge is presumed to be lowered so that the corona discharge occurs in a stable manner as prevented from concentrating on some of the pointed ends due to the working errors or mounting errors of the poles. Accordingly, the current value of the primary winding of the transformer can be reduced for power saving while the air ionization efficiency can be increased. In addition, the elongated first and second poles are able to generate a large quantity of corona discharge at a time, thereby producing a large quantity of ozone.
According to one preferred mode of the invention, the ion generator has an arrangement wherein the first poles are disposed at plural places arranged peripherally of the second pole as presenting their respective flat surfaces to a peripheral surface of the second pole (claim 6). This arrangement provides an even greater ozone generation.
The ion generator may have an arrangement wherein the first pole is formed with plural lines of pointed *z ends whereas the second pole is disposed in correspondence to each of the lines of pointed ends (claim 7). This arrangement also provides a greater ozone generation.
It is preferred in the inventive ion generator that the first pole is formed from tungsten (claim 2). In this case, the pointed ends of the first pole resist oxidation by ozone even if they are heated to about 1000xc2x0 C. by the corona discharge so generated and hence, the subsequent generation of corona discharge will not be obstructed. In addition, tungsten does not act as a catalyst assisting the reaction of ozone on the surface of the first pole.
The ion generator of the invention may be provided in an air charging system for supplying air to an internal combustion engine (claim 3). In this case, a highly efficient combustion of the internal combustion engine is ensured.
The ion generator of the invention may have an arrangement wherein the intake port of the casing is provided with a dust filter whereas the exhaust port is provided with a silocco fan for discharging ionized air (claim 4). In this case, air filtered by the dust filter may be continuously introduced into the casing, efficiently ionized and discharged out of the casing. This provides for an efficient supply of ozone to a combustion apparatus such as a boiler, incinerator or the like.
The ion generator of the invention may have an arrangement wherein the intake port of the casing is provided with a dust filter whereas the exhaust port is provided with an air pump for discharging ionized air (claim 5). In this case as well, the air filtered by the dust filter may be continuously introduced into the casing, efficiently ionized and discharged out of the casing.
The ion generator of the invention may further comprise a solar panel for converting the radiation energy of the solar light to an electrical energy, and a power source section comprising a storage battery for storing the electrical energy (claim 6). In this case, the ion generator is portable because the current for corona discharge is supplied from the power source section. Equipped with the solar panel and designed for automatic storage of the electrical energy, the ion generator can be used for an extended period of time without recharging from utility power.